Zakharovs most important work was the complete reconstruction of the new main Admiralty Building in St Petersburg in connection with the Admiraltys new role as the Naval Ministry. This Neo-classical building, unfinished at Zakharovs death and completed by the architects Ivan Gomzin and August Ricard de Montferrand, among others, embodies the best progressive features of Russian architecture and brought its designer international fame. Zakharov retained the dimensions and layout of the old Admiralty Building, which was founded during the reign of Peter I on the banks of the River Neva opposite the Peter and Paul Fortress and rebuilt by Ivan Kuzmich Korobov (1700-1747) in the 1730s in the form of two long, parallel ?-shaped buildings, a central tower crowned with a spire providing access between them. To reflect the dual role of the complex as a shipyard and main administration building, Zakharov preserved its division into two units, rebuilding the central tower and spire.